Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins.
Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins.
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DOI：
10.1128/jvi.02219-17
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发表时间：
2018-04-15
影响因子：
5.4
通讯作者：
Dixon LK
中科院分区：
文献类型：
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作者：
Jancovich JK;Chapman D;Hansen DT;Robida MD;Loskutov A;Craciunescu F;Borovkov A;Kibler K;Goatley L;King K;Netherton CL;Taylor G;Jacobs B;Sykes K;Dixon LK
非洲猪瘟病毒（ASFV）引起家猪急性出血热，具有很高的社会经济影响。没有可用的疫苗，限制了控制的选择。虽然减毒活ASFV可以诱导高达100%的保护，对致命的挑战，很少知道的抗原，诱导这种保护性反应。为了鉴定其他ASFV免疫原性和潜在的保护性抗原，我们在用于基因疫苗接种的单个质粒和重组牛痘病毒中克隆了47个病毒基因。选择这些抗原以包括具有不同功能和表达时间的蛋白质。通过DNA初免和重组牛痘病毒加强免疫将多达22种抗原的混合物递送至猪群。通过干扰素γ酶联免疫吸附斑点（ELISpot）试验测定猪免疫淋巴细胞对单个重组蛋白和ASFV的反应，以确定始终诱导最高反应的抗原子集。然后通过DNA初免和重组牛痘病毒加强将所有47种抗原递送给猪，并用致死剂量的ASFV分离株格鲁吉亚2007/1攻击猪。尽管猪出现了与急性ASFV一致的临床和病理体征，但与对照猪的水平相比，用表达ASFV抗原的载体免疫的那些猪的血液和几种淋巴组织中的病毒基因组水平显著降低。缺乏疫苗限制了控制非洲猪瘟的选择。基因修饰的ASFV减毒活疫苗的开发已经取得了进展，可以诱导对攻击的保护。然而，在现场使用这些可能存在安全问题。关于ASFV抗原可以诱导针对攻击的保护性免疫应答的信息很少。我们通过DNA免疫初免和重组牛痘病毒加强免疫将不同库中的单个基因递送给猪，进行了30%的ASFV抗原的大筛选。比较免疫猪对这些单个抗原的应答，以确定最具免疫原性的抗原。与用对照载体免疫的猪相比，用抗原池免疫的猪的致死性攻击导致血液和淋巴组织中病毒水平降低。新的免疫原性ASFV蛋白已被鉴定用于作为疫苗候选物的进一步测试。
African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia virus boost. The responses in immunized pigs to these individual antigens were compared to identify the most immunogenic. Lethal challenge of pigs immunized with a pool of antigens resulted in reduced levels of virus in blood and lymph tissues compared to those in pigs immunized with control vectors. Novel immunogenic ASFV proteins have been identified for further testing as vaccine candidates.